when you think about the plague the
black death of the 14th century
medieval cities overrun with rats stacks
of bodies
and those creepy plague masks might come
to mind but the plague isn't just
something of the past
it is still very much around and can
still be deadly
so maybe keep your plague mask handy
my wife and i were living in new york
and the news was on and she said to me
there's two cases of plague in manhattan
and of course the first thing i said
as an infectious disease doctor was how
cool is that
hi my name is larry lutwick i'm a
professor of medicine at the mayo clinic
school for medicine and science my
interest in plague comes from my work
with the program for monitoring emerging
diseases which
reports on and studies outbreaks
throughout the world
now when we're talking about plague
we're not just talking about one thing
there are actually three major types of
plague depending on what part of the
body is affected
septicemic pneumonic and bubonic which
is what we think of when we hear the
plague since it's the most common type
what is commonly called plague is an
infection
of animals and humans with a bacterium
called urcinia pestis
this bacterium mainly lives in small
rodents but it can make the jump from
animals to humans making it a zoonotic
bacteria
now there's usually a vector host and in
the case of the bubonic plague
it's the flea most of the time a person
is infected with clay
has an infected through a flea bite
where the flea tries to
feed on you and regurgitate some of the
bacteria from
the upper intestinal tract into the bite
site
then the orgasm starts to replicate and
spread
through the local lymphatic system into
the lymph gland
once there the bacteria begin producing
toxins that do two things
they disrupt the body's regular
inflammatory response and evade
detection by defense cells called
macrophages
so now with little standing in their way
the bacteria are able to multiply
quickly in the lymph nodes
with bubonic plague the classical
manifestation is the bubo which is an
extremely
tender very large swollen body lymph
node with redness around it
and it said that if you have an
individual who is sort of groggy or
somewhat altered related to the
infection just by pushing on the
booboo it's so tender that they tend to
wake up and move around and
you know yell at you but if you do come
across someone with a boobo
please don't try this other symptoms may
include fever
chills body aches nausea and vomiting
all of which can usually take anywhere
between one and seven days to pop
up but probably the most important thing
to keep in mind is that timing here is
crucial
because things can go downhill quickly
if treatment isn't started immediately
and that goes for all three types of
plague
if treatment for bubonic plague doesn't
work or is administered too late or if
the bubonic stage doesn't occur
then the bacteria can continue its
spread from the lymph nodes into the
bloodstream
where it starts to multiply called
septicemic plague this is a much more
serious infection
where patients can up shock bleeding
into the skin and most recognizably the
skin can turn dark and die
and that's presumably what the black
death was
the septicemic phase of the illness
and then there's mnemonic plague which
is the most dangerous out of the three
where the bacteria has spread into the
lungs it's the rarest form of plague but
unlike bubonic and septicemic
pneumonic plague adds a wild card human
to human transmission
with a bacteria spreading via infectious
respiratory droplets
and because of its potential as a
biological weapon the plague is a
category a pathogen in the u.s
it's not going to go away because
it's endemic in an animal population
that's one of the reasons why we were
able to eradicate
small problems because smallpox was not
a zoanosis we were able to immunize
around it
and eradicate it diseases that are
zoonosis
pose a particularly difficult problem in
eradicating
but the good news is that we're no
longer in the 14th century and we've got
plenty of antibiotics to treat plague
which
usually seem to do the trick currently
fewer than a dozen cases pop up in the
u.s
on average every year and between 1 and
3 000 cases are reported around the
world
there have been vaccines there was a
killed plague vaccine that was used in
the military
through the vietnam war it's no longer
really used there are some other
vaccines that are undergoing
studies in various parts of the world
but currently there's not a licensed
plague vaccine in the united states
it's difficult to get adequate funding
to produce good safe effective vaccines
for diseases that don't really affect
the developed countries